What it is Pekegno it is not like a normal bottom feeder pin that goes all the way through. There is a fixed pin that goes through to the top of the positive post. By default it has what is a screw cap that is not the bottom feeder screw cap. The bottom feeder screw cap with hole in it is what you will use to screw into the fixed 510 pin.

The default screw cap with no hole in it is on tight but can be removed. Once that is done just screw in the bottom feeder screw cap. I have to call it a cap because that is what it is like. Not bad and works well. On the top of the positive post you need to take one of the grub screw and screw it in if you want to use the bottom feeder to fill the tank up. The tank post in the glass has two holes in it that will allow juice to refill it every time you squeeze the bottle. If you don't put the grub screw into the top of the positive post then the juice will come out the top of the post. Which is fine.

Using it on the kangertech 160w bottom feeder. Works great.

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